There has been widely used a system that detects a current position of a wiper blade on a glass surface and makes the wiper blade perform reciprocating wiping operation between an upper inversion position and a lower inversion position based on the detection data. As a control mode in such a wiper system, there is known a method that uses an elapsed time from an inversion position, angle information of a motor shaft, a count number of pulses output with motor rotation, and the like (hereinafter, abbreviated as “elapsed time, etc.”) to detect a blade position and controls a wiper motor based on the detected blade position. In this method, for example, the elapsed time, etc., and the blade position (angle) are previously associated with each other and, thereby, a current position of the blade is detected based on the elapsed time, etc. Then, a target speed is set based on the detected blade position, and a motor is feedback-controlled according to the set target speed, whereby the wiper blade is reciprocated at a predetermined wiping cycle.